Technologies in Breast Cancer... Video Transcript

Participants

R. Edward Coleman MD

Summary

Already used to evaluate such conditions as lung cancer and brain tumors, PET scanning is emerging as a useful tool to help determine how far breast tumors have spread. On our webcast, we'll visit a leading breast PET center at the Duke University Medical Center to watch this fascinating technology in action. We'll take you through the process from beginning to end, and talk to a leading breast radiologist about how PET scanning works and how it is used to diagnose breast cancer.

Webcast Transcript

I am Edward Coleman, professor of radiology and director of the PET facility at Duke University Medical Center.

Positron emission tomography is frequently referred to as PET imaging, and PET imaging is just one of several imaging modalities for evaluating the breast.

The other imaging modalities that have been used for evaluating the breast include mammography, which is the most common and which is used to routinely screen women for breast cancer.
If there's an abnormality seen on mammography or a suspicious lesion palpated in the breast, ultrasonic imaging -- ultrasound -- is another way to evaluate the breast.  So PET is one of several imaging modalities that can be used for taking pictures of the breast to see if cancer is present in the breast tissue.

This particular patient has known breast cancer, and the question is whether she has involvement of the breast cancer in the axillary lymph nodes.  In addition, we'll be looking to determine if it has been spread anywhere else, but the major question that the clinician has referred the patient for is, is there spread of the breast cancer to the axillary lymph nodes?

When a patient comes to the PET facility or for a PET scan, they initially come to the reception desk, where they fill out patient information so that we have the exact reason why the scan is being performed and other information related to the disease. The patient then is taken into a room where the fluorodeoxyglucose is administered into a vein, usually into a vein in the arm.

We use fluorodeoxyglucose, an analog of sugar -- which is the same sugar that we eat in our diets every day.  We take that molecule of sugar and put fluorine 18, a small amount of radioactivity, onto this sugar and administer that intravenously.  By administering this radiolabeled molecule, we are able to look at the biology in the body.  We've known for a long period of time that cancers use more sugar than other tissues in the body, so by injecting this radioactive glucose, fluorodeoxyglucose, we are able to determine where tumors are in the body.

The patient is asked to stay quiet for the 30 to 45 minute uptake period.  During this time, the radioactive sugar is circulating in the blood.  It is accumulating in sites where it's going to accumulate.  If the patient has a tumor, it will be accumulating there.  The patient then is taken into the scanner room, where they are placed on the table.  And gentle restraints are used to remind the patient not to move during the procedure.

The table moves through the PET scanner during this 45-minute period about six or seven times. While the scan is going on, the technologist has to assure that the patient is moving through the scanner in the right time and the right number of bed positions.

While the patient is in the PET scanner, the PET scanner is detecting the radiation that is coming out of the patient's body.  It's detected, then the computer reconstructs the images to produce the exact distribution of where the radioactivity is in the body.

At the end of that time, the technologist uses the computer to process the images.  That takes approximately 3 to 5 minutes after the patient is off the scanner.  So the machine is used to detect the radiation as it comes out of the body, and that information is used to make the images that are interpreted.

These are the images that were acquired on the patient by the PET scan that was just done.